From: Olaf Hering <olaf@aepfle.de>
To: xen-devel@lists.xen.org
Subject: missing unplug of SCSI devices in HVM guest
Date: Wed, 24 Aug 2016 11:24:25 +0200 [thread overview]
Message-ID: <20160824092425.GA23354@aepfle.de> (raw)
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Does anyone remember why the the vbd frontend drivers also claim the
SCSI disks, but the vbd backend in qemu has no unplug support for SCSI?
The current situation for qemu-xen and qemu-xen-traditional is that both
will create an emulated LSI controller with disk=[vdev=sda]. The
xenlinux and pvops frontend drivers will claim the disk, but the
sym53c8xx will see and claim it as well. As a result each disk is
visible twice. One has to blacklist the sym53c8xx driver to avoid that.
What should be done to fix this?
#1 new unplug protocol for SCSI, but old guests dont know about it
#2 reuse IDE flag to also unplug SCSI. This would cover pvops and guests
where xenlinux based xen-platform-pci.ko is loaded before
sym53c8xx.ko. It would break guests with frontend drivers that do not
claim SCSI disks, the SCSI disk would disappear (if such frontends
really exist).
#3 do not provide SCSI if guest has PV drivers
Olaf
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next reply other threads:[~2016-08-24 9:24 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-24 9:24 Olaf Hering [this message]
2016-09-06 16:42 ` missing unplug of SCSI devices in HVM guest George Dunlap
2016-09-07 10:38 ` Paul Durrant
2016-09-07 10:48 ` Olaf Hering
2016-09-07 10:53 ` Paul Durrant
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